1. Field of the Invention
The present invention relates to a liquid crystal applicator and a liquid crystal application method for applying a liquid crystal on a substrate, and an apparatus for manufacturing a liquid crystal panel having the liquid crystal applicator.
2. Description of the Related Art
A liquid crystal panel for use with a display device for the information equipment has a liquid crystal filled into a gap (liquid crystal pouring space) of as large as about several xcexcm that is formed by inserting a spacer between a pair of glass substrates. One method for filling the liquid crystal between the substrates involves forming a filler hole 102 through a panel 100 consisting of a pair of substrates laminated by an adhesive 101 and pouring the liquid crystal through the filler hole 102 owing to a differential pressure, as shown in FIG. 9.
A liquid crystal container 105 for containing a liquid crystal 104 and the panel 100 are placed within a vacuum vessel, and the filler hole 102 of the panel 100 is immersed in the liquid crystal 104, as shown in FIG. 9. Thereafter, the vacuum vessel is supplied with a gas and placed in a pressurized (or atmospheric pressure) state. Since a liquid crystal pouring space 103 formed by the substrates and the adhesive 101 has been evacuated, the liquid crystal 104 enters from the liquid crystal container 105 into the liquid crystal pouring space 103 owing to a differential pressure. If the liquid crystal space 103 is filled with the liquid crystal 104, the filler hole 102 is sealed with the adhesive.
However, there was a problem that the liquid crystal pouring method of FIG. 9 had a longer pouring time and the lower productivity, along with the increased size of the panel 100 and the smaller panel gap size. Instead of this pouring method, a method of laminating one substrate with another substrate after applying the liquid crystal on the one substrate, employing a dispenser 106 as shown in FIG. 10.
In this dispenser system, the liquid crystal 104 within a tank 108 is force fed to the dispenser 106, using a gas pressure of the compressed air to discharge liquid droplets of the liquid crystal 104 through a nozzle 107 of the dispenser onto a substrate 109. The substrate 109 has applied an adhesive 110 serving as a sealing agent and the liquid crystal droplets 104 are dripped uniformly on a region surrounded by the adhesive 110 by moving the substrate 109 or dispenser 106. Thereafter, this substrate 109 is laminated with the other substrate (not shown) to produce the liquid crystal panel.
However, with the related-art dispenser system, since the liquid crystal 104 is force fed to the dispenser 106, using a gas pressure, and discharged, there is a great dispersion in the discharge amount in a situation where the discharge is started or stopped, such as a pressure rise delay at the start of discharge, resulting in a problem that the quantitative stability in the discharge amount is impaired. Also, since the discharge is turned on or off under the control of gas pressure, the resolution of discharge amount is poor, and the quantitative stability is impaired as the required discharge amount is smaller.
It is an object of the invention to provide a liquid crystal applicator of dispenser system that has the improved quantitative stability and a liquid crystal application method, and an apparatus for manufacturing a liquid crystal panel having the liquid crystal applicator.
The embodiments of the present invention will be set forth below with reference to FIGS. 1, 5 and 8.
(1) In order to accomplish the above object, according to a first aspect of the invention as shown in FIG. 1, there is provided a liquid crystal applicator for applying a liquid crystal on a substrate 12, comprising a liquid crystal discharge unit 1 having a piezoelectric transducer 1b for discharging a liquid crystal 5a due to a vibration of the piezoelectric transducer 1b, a switch unit 6, 8, 9, 11 for switching whether the liquid crystal 5a discharged from the liquid crystal discharge unit 1 is led to the substrate 12, and a controller 15 for controlling the switch unit 6, 8, 9, 11 so that a predetermined amount of liquid crystal 5a may be applied on the substrate 12.
(2) According to a second aspect of the invention as shown in FIG. 5, in the above-mentioned liquid crystal applicator, it is preferable that the switch unit comprises a shutter plate 30 for capturing the liquid crystal 5a discharged from the liquid crystal discharge unit 1, and a shutter plate driver 31 for driving the shutter plate 30 to move into or from a path of the liquid crystal.
(3) According to a third aspect of the invention as shown in FIG. 1, in the above-mentioned liquid crystal applicator, it is also preferable that the switch unit comprises an ionizer 6 for ionizing the liquid crystal 5a discharged from the liquid crystal discharge unit 1, a capture member 11 disposed in a discharge direction of the liquid crystal 5a and capturing the liquid crystal 5a, and a deflector 9 for deflecting the ionized liquid crystal 5a to be led to the substrate, wherein the controller 15 controls the ionizer 6 to be turned on or off so that a predetermined amount of liquid crystal 5a maybe applied on the substrate 12.
(4) According to a fourth aspect of the invention as shown in FIG. 8, there is provided an apparatus for manufacturing a liquid crystal panel 40 for laminating a first substrate 12B and a second substrate 12A having a liquid crystal dripped on one face so that the liquid crystal 5 may be provided between the first substrate 12B and the second substrate 12A to form a liquid crystal panel 50, wherein the liquid crystal is applied on one face of the second substrate 12A, employing the liquid crystal applicator 41 according to any one of the first to third aspects of the invention.
Though the embodiments are set forth with reference to the accompanying drawings to make the understanding easier, the invention is not limited to the above embodiments.